Student or Learner
Is it correct to say "Is the telephone number updated yet"? If so, what does it really mean from a grammar sense.
I would go with "Has the .... been updated yet" too. It might be appropriate to use "updated" but it depends on the context. For example, there are some business directories which hold the telephone numbers, fax numbers and website addresses of thousands of businesses. They periodically update their records to ensure that the details are correct. In that scenario, it's entirely possible that someone might ask "Has the telephone number been updated yet?"
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.